<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
  document.documentElement.offsetHeight;
  var n = document.getElementById("a").firstChild;
  n.data = "";
  n.data = "z";
}

</script>
</head>
<body onload="boom();" style="-moz-column-count: 3;"><span id="a">x&#x202E;</span><span>y</span></body>
</html>
